Mollie

“Please transfer within 14 days” gets paid slower than a button does. Connect the Mollie account your agency already has and every open invoice gains a payment link: iDEAL, Bancontact, cards, SEPA direct debit or PayPal, whatever your Mollie profile has switched on. The payer goes to Mollie’s own checkout and what comes back here is an id, so schakl. never sees card data. As soon as Mollie confirms, an ordinary payment line appears on the invoice with nobody retyping it.

Rehearse on the test key first

A green settings screen tells you your key is valid, and nothing more. Whether iDEAL is actually switched on at Mollie, whether your edge forwards the callback path, and whether the amount is right only show up on a real payment. So walk the whole route once on the test key: make a payment link on an open invoice, pay it, and watch the payment line appear. Mollie provides test cards and magic amounts that deliberately force a specific failure, so you also see what happens when it goes wrong. Two things to know: test mode supports euro only, and a test payment deliberately never settles anything on the invoice.

Where to find it

Two places, no more. You connect the account at Instellingen → Mollie (Settings → Mollie), in the group Integraties (Integrations) — also findable by searching “ideal”, “creditcard”, “betaallink” or “webhook”. The work itself happens on the invoice: Facturatie → Facturen (Invoicing → Invoices) → the invoice → the Online betalingen (online payments) card. Mollie deliberately contributes no menu item and no client panel; a payment provider is not a place you go.

Connecting

1. Get your API key from Mollie. Mollie dashboard → Developers → API keys. A test key starts with test_, a live key with live_. They are fully separate worlds, and one key belongs to exactly one website profile.

2. Make sure you hold the permission. Instellingen → Rollen (Settings → Roles) → mollie.settings.manage (“Mollie-accounts beheren”). Only the admin role holds it by default, and the client role never does.

3. Add the account. Instellingen → Mollie → Account toevoegen (add account). Fill in Naam (the name you recognise this account by, for instance the profile at Mollie), optionally a Leverancier (supplier) from your own list, and paste your API-sleutel (API key). Save. The screen stores the key encrypted and verifies it straight away.

4. Read what comes back. Modus (mode) shows Live or Test, derived from the key’s own prefix and never entered. Betaalmethoden (payment methods) lists what Mollie itself reported back: this is the only place “iDEAL is not switched on” is visible before a client meets it at checkout. If Mollie rejects the key you get “Probleem met de sleutel” with Mollie’s own wording verbatim behind it. Sleutel controleren (check key) re-runs the probe at any time.

5. Allow the Meldingsadres through your edge. The screen prints the exact per-account URL that Mollie calls, with a Kopiëren (copy) button. See below for why this is the step that matters most.

6. Rehearse with the test key. Open an invoice, create a Betaallink, follow the checkout, force a final status on Mollie’s test screen and watch the state on the card move. Then rotate the live key in (Instellingen → Mollie → account → API-sleutel), or add the live key as a second account and set the test one to Niet in gebruik (not in use).

Nothing else needs configuring in Mollie’s dashboard beyond enabling the payment methods you want. schakl. sends the notification URL with each individual payment, so there is no dashboard webhook to register.

The Meldingsadres: the step that fails silently

Allow this path, or payments are collected and never booked

Mollie calls the Meldingsadres (notification URL) whenever a payment changes, with no session and no cookie. If an access proxy sits in front of your installation (Cloudflare Zero Trust, for example), Mollie meets a login page instead of your API. So add a bypass rule for that path only: public, no Access policy. Nothing anywhere reports an error if you forget, and nobody is alerted.

Two other ways this breaks:

• A 301 or 302 redirect in front of the API throws the message body away. A trailing-slash redirect, or an http-to-https bump, has to be a 307 or 308.
• Rotating the API key changes the Meldingsadres. The secret underneath it is regenerated. Copy the new URL into your edge rule after every rotation.

Do not pin Mollie to an IP allowlist. Mollie says so themselves: the published range moves.

Getting an invoice paid

An open (issued) invoice carries the Online betalingen card.

• As staff you press Betaallink (payment link): that creates a Mollie checkout for the amount still outstanding. You then pass it on with Betaalpagina openen (open payment page) or Link kopiëren (copy link).
• The client sees Nu betalen (pay now) in the same place in the portal. The portal never reads which accounts you connected; it reads only whether a payment provider is active and whether this document still has something outstanding.
• The state follows along: Wacht op betaling (waiting), In verwerking (processing), Gereserveerd (reserved), Betaald (paid), Mislukt (failed), Verlopen (expired) or Geannuleerd (cancelled), with the moment the link was created beside it.
• If it reads “Ontvangen, nog niet geboekt” (received, not booked yet), Mollie confirmed the payment but it has not been processed here. Status ophalen (check status) fetches it.

The amount never comes from the button: schakl. recomputes what is outstanding at that moment, and refuses an invoice that is not open or has nothing left to collect. Pressing pay twice does not open two payments either — a live checkout for exactly this account and this amount is reused.

Every hour at :25 schakl. re-asks about the payments that have not come to rest and repairs whatever a missed callback left behind, looking back seven days. That turns a blocked notification URL into a delay rather than an incident, but it is not a substitute: fix the edge rule.

Permissions

Permission	What it opens	Held by default
mollie.settings.manage	The Instellingen → Mollie screen: adding accounts, rotating keys, verifying and removing them	Administrator (Administrator)
invoicing.payment.link	Starting an online payment (Betaallink / Nu betalen) and fetching its status	Administrator (Administrator, everything), Client (Client, their own invoices only)
invoicing.payment.write	Registering a payment by hand	Administrator (Administrator)
settings.providers.read	Optional: without it the Leverancier field is hidden rather than offered empty	Administrator, Member, Client (Administrator, Member, Client)

There is deliberately no mollie.payment.*. Starting a payment is an act on an invoice, not an act on Mollie, so it declares invoicing.payment.link. And a client paying their own invoice needs exactly that and nothing more: invoicing.payment.write would let them declare an invoice paid.

Good to know

• A test payment books nothing, ever. It runs the whole loop, Mollie reports it as paid, and the card says “Testbetaling: niet geboekt op deze factuur” (test payment: not booked on this invoice). The invoice stays open. That is deliberate: rotating a test key to a live one later cannot make an old test payment real.
• Live beats test. With one live and one test account, schakl. picks the live key. Two live accounts stay ambiguous on purpose (“Kies welke gebruikt moet worden” — choose which one to use); resolve it by setting one to Niet in gebruik.
• Reserved is not paid. Money held is not money moved, so nothing is booked against it. Only a genuinely paid payment produces a payment line.
• Payment methods are switched on at Mollie, not here. The list on the screen is an observation. In test mode Mollie also reports methods that are still pending, so a test key can legitimately show more than the live key will.
• There is no second place the mode is stored. Live or test always follows the key. An unrecognised prefix is read as live, because a misread key that books nothing is less bad than a real payment quietly filed as a test.
• Deleting an account changes nothing at Mollie, and the payments made through it stay on their invoices.
• If your licence expires you can no longer connect a new Mollie account or rotate a key, while the recording of payments already made keeps working.
• This integration cannot refund. Do that in Mollie’s dashboard; in schakl. you correct the invoice with a credit note and record the money going back with Terugbetaling registreren (register refund). Mandates, recurring payments and Mollie-side subscriptions are not in it either.
• Do not expect a fixed expiry. It differs per method (iDEAL fifteen minutes, cards half an hour, Bancontact an hour, PayPal six hours) and it is Mollie’s to decide. schakl. does not predict it.
• The QR code on your invoice is not a payment link. Switch it on at Instellingen → Facturatie → Sjablonen → Indeling → QR-code (Settings → Invoicing → Templates → Layout) and it points at the invoice’s page in the client portal. A payment link is a key, and a key does not belong on paper.

Read next

Invoicing Where the invoice comes from and what happens to a payment.

Client portal The screen your client sees Nu betalen on.

All integrations What else can be connected, and what is available today.